<text><span class="style10">lements and the Periodic Table (2 of 8)</span><span class="style7">The atomic number of bismuth is 83, and this number of protons represents the upper limit for a stable nucleus. Beyond 83, all elements are unstable, although their radioactive decay may be so slow that some of them, such as thorium and uranium, are found in large natural deposits. The largest atomic number so far observed is 109, but only a few atoms of this element have been made artificially, so little is known about it. Its name is unnilennium, meaning 'one-zero-nine'.</span></text>
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<text>ΓÇó QUANTUM THEORY AND RELATIVITYΓÇó ATOMS AND SUBATOMIC PARTICLESΓÇó CHEMICAL BONDSΓÇó CHEMICAL REACTIONSΓÇó METALS</text>